Lead frame plating apparatus

ABSTRACT

Disclosed herein is a lead frame plating apparatus. The lead frame plating apparatus comprises side inlets provided in the diagonal direction at opposite sides for supplying plating solution, a flow mixing room defined with an inner space in the longitudinal direction, a plating solution outlet for guiding the plating solution in the direction of nozzles, and a plating solution distribution part provided with the nozzles at an upper part of the plating solution outlet. Each nozzle is provided, at the lower end thereof, with a divergent-shaped expansion tube such that an inner diameter of the inlet of the expansion tube, larger than that of the nozzle, gradually decreases to an extent of the inner diameter of the nozzle. The lead frame plating apparatus supplies the plating solution through the nozzles with a uniform distribution.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lead frame plating apparatus, andmore particularly to a lead frame plating apparatus, which is providedwith nozzles, each having a shape for preventing the plating solutionfrom generating a vortex flow, and induces mixing of the platingsolution to uniformly distributing the plating solution into nozzles.

2. Description of the Related Art

A conventional lead frame plating apparatus will now be described withreference to the drawings.

Referring to FIG. 1, plating solution 3 supplied through a supply pipe 1is driven by a pump 5 and is then supplied to a distribution part 10defined with a predetermined space therein through a bottom part inlet7.

As shown in FIGS. 2 and 3, the conventional lead frame plating apparatusis provided with a plurality of distributing plates 12 inside thedistribution part 10, in order to induce a uniform flow of the platingsolution supplied from the bottom part inlet 7 to be guided into nozzles14 at an upper portion of the apparatus.

Each distributing plate 12 is formed with a plurality of hollow portions13, so that when the plating solution 3 passes through the hollowportions 13 of the distributing plates 12, the plating solution 3 isuniformly mixed.

Then, as shown in FIG. 1, the plating solution 3 is injected to an upperside through the nozzles 14, thereby performing a plating operation fora lead frame 17 which is restricted in its upward movement by a top partblock 16.

Meanwhile, since the conventional lead frame plating apparatus isprovided with a mask 19 under the lead frame 17, the plating solution 3injected through the nozzles 14 arrives only on predetermined portionsof the lead frame 17. Further, the plating solution 3, having fallen toa lower side, is guided to either side to flow along a passage definedat a lower portion of a guide plate 18.

In accordance with the conventional lead frame plating apparatus, thebottom part inlet 7 is provided at the center of a lower side of thedistribution part 10, and three or more distributing plates 12 are usedfor the uniform distribution when the plating solution from the bottompart inlet 7 flows to the nozzles 14. With the conventional lead frameplating apparatus, when the plating solution 3 passes through the hollowportions 13 of the distributing plates 12, vortex flow is generated,causing a detrimental loss in pressure.

Thus, in order to supply the set amount of fluid required for plating,the plating solution supply pump 5 should be increased in capacity.Further, an increase of pressure for supplying the plating solution 3raises the inner pressure of the distribution part 10, therebyincreasing the possibility of breakage of the apparatus and reducingdurability thereof.

Further, as shown in FIGS. 4 and 5, the nozzles 14 are mounted such thatwith a plurality of nozzles mounted on the upper side of thedistribution part 10, the plating solution 3 is injected to the upperside through each nozzle aperture 15 formed at each nozzle 15.

As described above, if the plating solution 3 is injected to the upperside through the conventional straight nozzles 14, the vortex flow ofthe plating solution 3 is generated, as shown in FIG. 6, near the inletof each nozzle, causing a decrease in the width of the fluid passage ofthe plating solution 3. Thus, the quantity of plating solution isreduced, thereby decreasing the injection rate of the plating solutionat the outlet of each nozzle.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above problems, and itis an object of the present invention to provide a lead frame platingapparatus, which supplies plating solution to nozzles with a uniformdistribution and with a reduced pressure loss.

It is another object of the present invention to provide a lead frameplating apparatus, which overcomes the problem of increased cost due tothe increased capacity of a supply pump for supplying plating solutioncompensating for the pressure loss occurring when the plating solutionis mixed, and which prevents a breakage of the apparatus due to anincreased inner pressure of the plating solution.

It is yet another object of the present invention to provide a leadframe plating apparatus, which prevents a decrease in the width of afluid passage of the plating solution by removing vortex flow generatednear the inlet of each nozzle, thereby increasing fluid quantity andflow rate of the plating solution injected from the nozzles.

In accordance with an aspect of the present invention, the above andother objects can be accomplished by the provision of a lead frameplating apparatus, comprising: side inlets provided in a diagonaldirection at opposite sides of the lead frame plating apparatus,respectively, for supplying plating solution; a flow mixing room definedwith an inner space in a longitudinal direction for the platingsolutions, flowing in through side inlets, to be mixed with each otherwhile flowing in parallel; a plating solution outlet for guiding theplating solution in the direction of the nozzles, the plating solutionoutlet having a cross-sectional area smaller than that of the flowmixing room; and a plating solution distribution part provided with thenozzles at an upper portion of the plating solution outlet, each nozzlebeing provided, at the lower end thereof, with a divergent-shapedexpansion tube such that an inner diameter of the inlet of the expansiontube, larger than that of the nozzle, gradually decreases to the extentof the inner diameter of the nozzle.

In accordance with the present invention, an excessively large-capacitypump is not required due to the structure which reduces pressure lossduring mixing the plating solution, so that cost reduction andprevention of breakage in the apparatus by an excessive inner pressurecan be obtained, and so that when the plating solution passes througheach nozzle, the vortex flow is not generated, thereby achieving aproper supply of the plating solution.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a structural view showing the main construction of aconventional lead frame plating apparatus;

FIG. 2 is a front view of the conventional plating apparatus;

FIG. 3 is a partially cut-away perspective view of FIG. 2;

FIG. 4 is a perspective view illustrating the plating apparatus withnozzles mounted thereon;

FIG. 5 is a side sectional view of the plating apparatus of FIG. 4;

FIG. 6 is a diagram illustrating flow of plating solution passingthrough one of the nozzles;

FIG. 7 is a perspective view of a lead frame plating apparatus accordingto an embodiment of the present invention;

FIG. 8 is a partially cut-away perspective view of another embodiment ofthe plating apparatus;

FIG. 9 is a front view of the plating apparatus;

FIG. 10 is a plane view of the plating apparatus;

FIG. 11 is a right-side sectional view of the plating apparatus;

FIG. 12 is a partially cut-away perspective view of the platingapparatus;

FIG. 13 is a side sectional view of the plating apparatus;

FIG. 14 is a side sectional view of a plating apparatus according toanother embodiment of the present invention;

FIG. 15 is a side sectional view of a plating apparatus according to yetanother embodiment of the present invention; and

FIG. 16 is a diagram illustrating flow of plating solution passingthrough one of the nozzles according to the embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferred embodiments of the present invention will be described indetail with reference to the annexed drawings. In the drawings, the sameor similar elements are denoted by the same reference numerals eventhough they are depicted in different drawings.

As shown in FIG. 7, a lead frame plating apparatus of the presentinvention is provided with side inlets 20 for supplying plating solutionat opposite sides of a flow mixing room 30 which has an oval-shapedcross section such that the plating solution, flowing in through eachside inlet, is mixed while flowing in parallel.

As shown in FIGS. 7 to 11, the side inlets 20 are provided at theopposite sides of the flow mixing room 30, respectively, in the diagonaldirection such that flow of the plating solution from one of the sideinlets 30 into the flow mixing room 30 is influenced as little aspossible by the flow from the other side inlet 30.

The lead frame plating apparatus of the invention is provided with aplating solution outlet 40 having a rectangular-shaped cross section atan upper side of the side inlets 20, and a plating solution distributionpart 60 provided with nozzles 70 at an upper side of the platingsolution outlet 40 to inject the plating solution toward an upper partof the apparatus.

The plating solution outlet 40 of the structure as described above maybe installed with one or two distributing plates 50 provided with aplurality of holes 51, as shown in FIG. 8.

Operation of the lead frame plating apparatus will be describedhereinafter.

As shown in FIGS. 7 to 12, when the plating solution flows into bothsides of the flow mixing room 30 through the side inlets 20, the platingsolution from each side inlet 20 flows in parallel and the kineticenergy of the flow changes into pressure to make the flow uniform.

A increased pressure on the plating solution in the flow mixing room 30causes the plating solution to flow to the upper side through theplating solution outlet 40, so that the plating solution is injected tothe upper part through the nozzles.

Since the flow of the plating solution from the side inlets 20 generatesa relatively low pressure at the inlets but it generates a high pressureat the opposite side of the flow mixing room, the balance between thepressures is not maintained. In order to compensate for the imbalancebetween them, the side inlets 20 are located at opposite sides of theflow mixing room. Further, as shown in FIG. 10, the side inlets 20 areprovided such that the flow of the plating solution from one of the sideinlets 20 does not interfere with the flow from the other side inlet 20.

In accordance with another embodiment of the invention, as shown in FIG.8, the plating solution outlet 40 is provided with one or twodistributing plates 50. Thus, the plating solution mixed in the flowmixing room 30 while flowing therein is mixed again when passing throughthe distributing plates 50, so that the plating solution is moreuniformly mixed.

As a result, compared with the conventional plating apparatus, theplating apparatus of the invention without or with a few distributingplates reduces the pressure loss of the flow due to the vortex flowgenerated when the plating solution passes through the distributingplates 50, and enhances durability of the lead frame plating apparatusdue to a reduced pressure in the plating apparatus.

Further, as shown in FIG. 13, each nozzle 70 mounted to the distributionpart 60 is provided with a first divergent-shaped expansion tube 80 atthe lower end portion. The first expansion tube 80 is mounted by beinginserted into the distribution part 60.

The first expansion tube 80 has a divergent shape in which an innerdiameter of the inlet of the first expansion tube 80, larger than thatof each nozzle 70, gradually decreases to an extent of the innerdiameter of each nozzle 70.

According to another embodiment of the invention, as shown in FIG. 14,each nozzle 70 is provided with a second divergent-shaped expansion tube82 protruding from an outer side of the distribution part 60.

According to yet another embodiment of the invention, as shown in FIG.15, a third divergent-shaped expansion tube 84 in each nozzle 70 has aprotruded part, similar to that of the second tube 84 as shown in FIG.14, on the outer side of the distribution part 60. However, the thirdexpansion tube 84 has a tubular shape, whereas the second expansion tube82 is shaped such that one end of the divergent shape adjoins to befixed to the distribution part 60 at a predetermined thickness.

In addition to the above embodiments, various embodiments can beapplicable within the spirit of the present invention wherein the lowerend of each nozzle 70 has a divergent shape.

Operation of the nozzles 70 will now described.

When the plating solution, having flowed in through the supply pipe,flows into both sides of the flow mixing room 30 through each side inlet20, the flow of the plating solution are in parallel with each other andthe kinetic energies of the flows change into the pressure to make theflows uniform.

A raised pressure on the plating solution in the flow mixing room 30causes the plating solution to flow to the upper side through theplating solution outlet 40. Then, the plating solution is uniformlymixed again to a predetermined extent inside the distribution part 60and is injected to the upper part through the nozzle 70 mounted on theupper side of the distribution part 60.

As shown in FIG. 16, the flow of the plating solution to the upper sidethrough each nozzle 70 is defined such that the plating solution 90flows from the expansion tube 80, 82 or 84, of which the diametergradually decreases, to the upper part through each nozzle opening 72.Here, the shape of the expansion tube 80, 82, or 84 prevents the flow ofthe plating solution 90 from generating the vortex flow, therebyavoiding the fluid passage from narrowing. Thus, compared with the priorart, the flow rate and the fluid quantity of the plating solution areincreased, so that the plating solution is properly supplied to the leadframe.

As is apparent from the description, in accordance with the presentinvention, there is an advantageous effect in that the plating solutionis supplied with a uniform distribution and with a reduced loss ofpressure, thereby enhancing plating efficiency.

Further, due to the structure maximally reducing the pressure loss whenthe plating solution is mixed, an excessively large capacity pump is notrequired, thereby reducing costs.

Further, since the plating solution in an excessive pressure forcompensating the pressure loss is not required to be supplied to theapparatus, the breakage of the apparatus due to a raised inner pressureis prevented, thereby enhancing durability.

Further, the expansion tube of the nozzle prevents the plating solutionpassing through the nozzle from generating the vortex flow, so that thequantity of the plating solution and the flow rate are increased,thereby enhancing reliability.

It should be understood that the embodiments and the accompanyingdrawings as described above have been described for illustrativepurposes and the present invention is limited by the following claims.Further, those skilled in the art will appreciate that variousmodifications, additions and substitutions are allowed without departingfrom the scope and spirit of the invention as set forth in theaccompanying claims.

1. A lead frame plating apparatus for injecting plating solution throughnozzles to a lead frame with a uniform distribution of the platingsolution, the apparatus comprising: side inlets provided in the diagonaldirection at opposite sides of the lead frame plating apparatus,respectively, for supplying the plating solution; a flow mixing roomdefined with an inner space in the longitudinal direction for theplating solutions, having flowed in the through the side inlets, to bemixed with each other while flowing in parallel; and a plating solutionoutlet for guiding the plating solution in the direction of nozzles, theplating solution outlet having a cross sectional area smaller than thatof the flow mixing room.
 2. The apparatus as set forth in claim 1,wherein the plating solution outlet is installed with a distributionplate provided with a plurality of holes.
 3. The apparatus as set forthin claim 1, the apparatus further comprising: a plating solutiondistribution part provided with the nozzles at an upper side of theplating solution outlet, each nozzle being provided, at the lower endthereof, with a divergent-shaped expansion tube such that an innerdiameter of the inlet of the expansion tube, larger than that of thenozzle, gradually decreased to the extent of the inner diameter of thenozzle.
 4. The apparatus as set forth in claim 3, wherein the expansiontube at the lower end of the nozzle is mounted by being inserted intothe inside of the plating solution distribution part.
 5. The apparatusas set forth in claim 3, wherein the expansion tube at the lower end ofthe nozzle is mounted in a state of being protruded from an outer sideof the plating solution distribution part.
 6. The apparatus as set forthin claim 2, the apparatus further comprising: a plating solutiondistribution part provided with the nozzles at an upper side of theplating solution outlet, each nozzle being provided, at the lower endthereof, with a divergent-shaped expansion tube such that an innerdiameter of the inlet of the expansion tube, larger than that of thenozzle, gradually decreased to the extent of the inner diameter of thenozzle.